Wireless communications systems are used in a variety of telecommunications systems, television, radio and other media systems, data communication networks, and other systems to convey information between remote points using wireless transmitters and wireless receivers. A transmitter is an electronic device which, usually with the aid of an antenna, propagates an electromagnetic signal such as radio, television, or other telecommunications. A receiver is an electronic device which receives and processes a wireless electromagnetic signal. A transmitter and receiver may be combined into a single device called a transceiver.
Many transmitters may include a drive amplifier or gain stage that may increase the power of the transmitted signal, but also may increase the power consumption of the transmitter. Additionally, the bias voltage used to drive the components of a transmitter may experience various voltage drops across internal resistances of the transmitter that may reduce the voltage headroom of the transmitter. The voltage headroom may be associated with the amount of voltage used to drive components of the transmitter and may be affected by the power of a radio frequency (RF) signal communicated through the transmitter. Accordingly, the output power of an RF signal transmitted by the transmitter may be limited because a reduction in voltage headroom may negatively affect the performance of the transmitter. Further, current sinking through the internal resistances of the transmitter may increase the power consumption of the transmitter.
Many transmitters are also configured to transmit RF signals using a plurality of transmission protocols, where different design considerations may apply for the different transmission protocols. Additionally, transmitters may be configured to transmit RF signals over a broad frequency range, where different design considerations may apply for different frequencies within the frequency range.